The adolescent period is crucial for optimizing future bone health because bone accumulates rapidly during these years and accounts for up to half of adult peak bone mass (PBM). In addition, PBM is a strong predictor of bone fragility later in life. Calcium intake during this period is critical for adequate bone mineralization. Inadequate calcium intakes during adolescence could lead to low bone mass and increased risk of fractures while adequate calcium intakes increases bone mass and prevents bone loss and fractures later in life. Calcium intake is precisely the nutrient most deficient in the diets of US adolescents, wih only 30% meeting the recommended level of calcium. A strategy to maximize bone mineralization during this critical period is to increase the absorption of the calcium being consumed. This could be achieved by supplementing diets with certain non-digestible carbohydrates, such as soluble corn fiber (SCF). These fibers are fermented by bacteria in the lower intestine producing short-chain fatty acids, which in turn solubilize minerals in the gut thereby improving their absorption. Studies in rats show that SCF is the fiber that results in greatest bone mass and resistance to fractures compared to other fibers. The few studies in humans have demonstrated that supplementing adolescents with SCF results in the greatest increase in calcium absorption. However, there are no studies determining the long-term effects of SCF on bone mass and bone biomarkers in humans. It is necessary to test if this increase in calcium absorption with SCF supplementation translates into an increase in bone mass in humans, particularly during the period of adolescence growth spurt. Therefore, the primary aim of this proposal is to determine the effects of SCF supplementation for 1 year on bone metabolism in growing adolescents compared to controls. For the proposed study, a randomized double-blinded placebo controlled clinical trial will be conducted in 168 healthy adolescents aged 11-14 years, equally randomly assigned to one of three intervention groups: SCF (12 g/d, administered twice a day), SCF + calcium (12 g/d of SCF + 600 mg/d of elemental calcium carbonate, twice a day), or placebo (0 g/d of SCF or calcium, administered twice a day). Bone metabolism and bone related biomarkers will be assessed at baseline and at 12 months. All the study visits will be conducted in the Puerto Rico Clinical and Translational Research Consortium, located in the University of Puerto Rico, Medical Sciences Campus. If supplementing diets with SCF lead to significantly higher bone mass during adolescence, this could help to achieve the genetic potential for PBM and to start adult life with stronger bones. Fortifying different food matrices with SCF or adding SCF to dietary supplements may be a cost effective intervention at the population level for bone health than increasing dairy products consumption, particularly in adolescents. Given that the antecedents to osteoporosis risk factors begin in adolescence and track into adulthood, intervening in adolescence has tremendous potential as means for preventing osteoporotic fractures later in life and minimizing its economic impact.